A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-energy exhaust gas flow. The high-energy exhaust gas flow expands through the turbine section to drive the compressor and the fan section.
Turbine section operating temperatures are typically beyond the capabilities of component materials. Due to the high temperatures, air is extracted from other parts of the engine and used to cool components within the gas path. The increased engine operating temperatures provide for increased operating efficiencies.
Additional engine efficiencies are realized with variable compressor and turbine vanes that provide for variation in the flow of gas flow to improve fuel efficiency during operation. A stagnation point on a leading edge of a vane changes with movement of the vane about a pivot axis. The high temperatures encountered within the turbine section can cause unbalanced temperatures as the stagnation point shifts during operation. The unbalanced temperatures can lead to undesired decreases in engine efficiencies and vane operation.
Turbine engine manufacturers continue to seek further improvements to engine performance including improvements to thermal, transfer and propulsive efficiencies.